{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,25]],"date-time":"2025-10-25T21:57:02Z","timestamp":1761429422006,"version":"build-2065373602"},"reference-count":52,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2021,11,15]],"date-time":"2021-11-15T00:00:00Z","timestamp":1636934400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Reflected shortwave (SW) solar radiations at the top of atmosphere from Clouds and the Earth\u2019s Radiant Energy System (CERES), Modern Era-Retrospective analysis for Research and Applications version 2 (MERRA-2), and ECMWF Reanalysis 5th Generation (ERA5) are examined to better understand their differences in spatial and temporal variations (seasonal and diurnal cycle timescale) with respect to the observations from the Earth Polychromatic Imaging Camera (EPIC) on the Deep Space Climate Observatory (DSCOVR) satellite. Comparisons between two reanalyses (MERRA-2 and ERA5) and EPIC reveal that MERRA-2 has a generally larger deviation from EPIC than ERA5 in terms of the SW radiance and diurnal variability in all seasons, which can be attributed to larger cloud biases in MERRA-2. MERRA-2 produces more ice\/liquid water content than ERA5 over the tropical warm pool, leading to positive SW biases in cloud and radiance, while both reanalyses underestimate the observed SW radiance from EPIC in the stratus-topped region off the western coast of US\/Mexico in the boreal summer. Himalaya\/Tibet region in the boreal spring\/summer and the midlatitude Southern Hemisphere in the boreal winter are the regions where MERRA-2 and ERA5 deviate largely from EPIC, but their deviations have the opposite sign. Vertical structures of cloud ice\/liquid water content explain reasonably well these contrasting differences between the two reanalyses. As two independent observations, CERES and EPIC agree well with each other in terms of the SW radiance maps, showing 2\u20133% mean absolute errors over the tropical midlatitudes. The CERES-EPIC consistency further confirms that the reanalyses still have challenges in representing the SW flux and its global distribution. In the CERES-EPIC observation differences, CERES slightly overestimates the diurnal cycle (as a function of local solar time) of the observed EPIC irradiance in the morning and underestimates it in the afternoon, while the opposite is the case in the reanalyses.<\/jats:p>","DOI":"10.3390\/rs13224595","type":"journal-article","created":{"date-parts":[[2021,11,15]],"date-time":"2021-11-15T20:46:47Z","timestamp":1637009207000},"page":"4595","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["An Investigation on Seasonal and Diurnal Cycles of TOA Shortwave Radiations from DSCOVR\/EPIC, CERES, MERRA-2, and ERA5"],"prefix":"10.3390","volume":"13","author":[{"given":"Young-Kwon","family":"Lim","sequence":"first","affiliation":[{"name":"Goddard Earth Sciences Technology and Research, University of Maryland, Baltimore County, Baltimore, MD 21250, USA"},{"name":"Global Modeling and Assimilation Office (GMAO), NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3490-9437","authenticated-orcid":false,"given":"Dong L.","family":"Wu","sequence":"additional","affiliation":[{"name":"Climate and Radiation Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA"}]},{"given":"Kyu-Myong","family":"Kim","sequence":"additional","affiliation":[{"name":"Climate and Radiation Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9814-9855","authenticated-orcid":false,"given":"Jae N.","family":"Lee","sequence":"additional","affiliation":[{"name":"Goddard Earth Sciences Technology and Research, University of Maryland, Baltimore County, Baltimore, MD 21250, USA"},{"name":"Climate and Radiation Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1175\/1520-0477(1996)077<0437:TNYRP>2.0.CO;2","article-title":"The NCEP\/NCAR 40-year reanalysis project","volume":"77","author":"Kalnay","year":"1996","journal-title":"Bull. Amer. Meteor. Soc."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2961","DOI":"10.1256\/qj.04.176","article-title":"The ERA-40 reanalysis","volume":"31","author":"Uppala","year":"2005","journal-title":"Quart. J. Royal. Meteor. Soc."},{"key":"ref_3","first-page":"25","article-title":"ERA-Interim: New ECMWF reanalysis products from 1989 onwards","volume":"110","author":"Simmons","year":"2006","journal-title":"ECMWF Newslett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"369","DOI":"10.2151\/jmsj.85.369","article-title":"The JRA-25 Reanalysis","volume":"85","author":"Onogi","year":"2007","journal-title":"J. Meteorol. Soc. Jpn."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1015","DOI":"10.1175\/2010BAMS3001.1","article-title":"The NCEP Climate Forecast System Reanalysis","volume":"91","author":"Saha","year":"2010","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3624","DOI":"10.1175\/JCLI-D-11-00015.1","article-title":"MERRA: NASA\u2019s Modern-Era Retrospective analysis for Research and Applications","volume":"24","author":"Rienecker","year":"2011","journal-title":"J. Clim."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"5419","DOI":"10.1175\/JCLI-D-16-0758.1","article-title":"The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)","volume":"30","author":"Gelaro","year":"2017","journal-title":"J. Clim."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1999","DOI":"10.1002\/qj.3803","article-title":"The ERA5 global reanalysis","volume":"146","author":"Hersbach","year":"2020","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"8166","DOI":"10.1002\/jgrd.50378","article-title":"Characterizing and understanding radiation budget biases in CMIP3\/CMIP5 GCMs, contemporary GCM, and reanalysis","volume":"118","author":"Li","year":"2013","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_10","unstructured":"Wang, H., Loeb, N.G., Su, W., Rose, F.G., Kato, S., and Doelling, D.R. (2017, January 26\u201328). Evaluating Radiative Fluxes in Current Reanalyses Using CERES EBAF-TOA and EBAF-Surface Ed4.0. Proceedings of the 2017 CERES Science Team Meeting, Greenbelt, MD, USA."},{"key":"ref_11","first-page":"145","article-title":"MERRA-2: Initial evaluation of the climate","volume":"43","author":"Bosilovich","year":"2015","journal-title":"NASA Tech. Memo."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1038\/s41561-019-0528-y","article-title":"Changes in atmospheric shortwave absorption as important driver of dimming and brightening","volume":"13","author":"Schwarz","year":"2020","journal-title":"Nat. Geosci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"4062","DOI":"10.1175\/1520-0442(2001)014<4062:QUINRU>2.0.CO;2","article-title":"Quantifying uncertainties in NCEP reanalysis using high-quality research vessel observations","volume":"14","author":"Smith","year":"2001","journal-title":"J. Clim."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Zhang, X., Liang, S., Wang, G., Yao, Y., Jiang, B., and Cheng, J. (2016). Evaluation of the Reanalysis Surface Incident Shortwave Radiation Products from NCEP, ECMWF, GSFC, and JMA Using Satellite and Surface Observations. Remote Sens., 8.","DOI":"10.3390\/rs8030225"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"D19105","DOI":"10.1029\/2003JD004457","article-title":"Calculation of radiative fluxes from the surface to top of atmosphere based on ISCCP and other global data sets: Refinements of the radiative transfer model and the input data","volume":"109","author":"Zhang","year":"2004","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"D13103","DOI":"10.1029\/2008JD009944","article-title":"Radiative forcing by long-lived greenhouse gases: Calculations with the AER radiative transfer models","volume":"113","author":"Iacono","year":"2008","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_17","first-page":"D00A13","article-title":"Evaluating cloud systems in the Met Office global forecast model using simulated CloudSat radar reflectivities","volume":"113","author":"Webb","year":"2008","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2925","DOI":"10.1175\/2009JAS2957.1","article-title":"Multiyear Evaluations of a Cloud Model Using ARM Data","volume":"66","author":"Henderson","year":"2009","journal-title":"J. Atmos. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1973","DOI":"10.1175\/JCLI-D-18-0445.1","article-title":"The Global Radiative Energy Budget in MERRA and MERRA-2: Evaluation with Respect to CERES EBAF Data","volume":"32","author":"Hinkelman","year":"2019","journal-title":"J. Clim."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"748","DOI":"10.1175\/2008JCLI2637.1","article-title":"Toward Optimal Closure of the Earth\u2019s Top-of-Atmosphere Radiation Budget","volume":"22","author":"Loeb","year":"2009","journal-title":"J. Clim."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1175\/JCLI-D-17-0208.1","article-title":"Clouds and the Earth\u2019s Radiant Energy System (CERES) Energy Balanced and Filled (EBAF) Top-of-Atmosphere (TOA) Edition-4.0 Data Product","volume":"31","author":"Loeb","year":"2018","journal-title":"J. Clim."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1002\/qj.828","article-title":"The ERA-Interim reanalysis: Configuration and performance of the data assimilation system","volume":"137","author":"Zelinka","year":"2011","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3642","DOI":"10.1002\/2014JD022887","article-title":"Climate variability and relationships between top-of-atmosphere radiation and temperatures on Earth","volume":"120","author":"Trenberth","year":"2015","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"7703","DOI":"10.1175\/JCLI-D-16-0089.1","article-title":"The seasonal cycle of the radiation budget and cloud radiative effect in the Amazon rainforest of Brazil","volume":"29","author":"Miller","year":"2016","journal-title":"J. Clim."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1175\/JTECH1712.1","article-title":"Angular distribution models for top-of-atmosphere radiative flux estimation from the Clouds and the Earh\u2019s Radiant Energy System in-strument on the Terra Satellite. Part I: Methodology","volume":"22","author":"Loeb","year":"2005","journal-title":"J. Amos. Ocean. Technol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"611","DOI":"10.5194\/amt-8-611-2015","article-title":"Next-Generation angular distribution models for top-of-atmosphere radiative flux calculation from CERES instruments: Methodology","volume":"8","author":"Su","year":"2015","journal-title":"Atmos. Meas. Tech."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Su, W., Liang, L., Wang, H., and Eitzen, Z.A. (2020). Uncertainties in CERES top-of-atmosphere fluxes caused by changes in accompanying iimager. Remote Sens., 12.","DOI":"10.3390\/rs12122040"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e2020EA001224","DOI":"10.1029\/2020EA001224","article-title":"Evaluation of CERES and CloudSat Surface Radiative Fluxes Over Macquarie Island, the Southern Ocean","volume":"7","author":"Hinkelman","year":"2020","journal-title":"Earth Space Sci."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Su, W., Liang, L., Myhre, G., Thorsen, T.J., Loeb, N.G., Schuster, G.L., Ginoux, P., Paulot, F., Neubauer, D., and Checa-Garcia, R. (2021). Understanding top-of-atmosphere flux bias in the AeroCom Phase III models: A clear-sky perspective. J. Adv. Model. Earth Syst., in press.","DOI":"10.1002\/essoar.10506924.1"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1829","DOI":"10.1175\/BAMS-D-17-0223.1","article-title":"Earth Observations from DSCOVR EPIC Instrument","volume":"99","author":"Marshak","year":"2018","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"177","DOI":"10.5194\/amt-11-177-2018","article-title":"Synoptic ozone, cloud reflectivity, and erythemal irradiance from sunrise to sunset for the whole Earth as viewed by DSCOVR spacecraft from the Earth-sun Lagrange 1 orbit","volume":"11","author":"Herman","year":"2018","journal-title":"Atmos. Meas. Tech."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3431","DOI":"10.1002\/jgrd.50353","article-title":"Evaluation of satellite and reanalysis products of downward surface solar radiation over East Asia: Spatial and seasonal variations","volume":"118","author":"Jia","year":"2013","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"e2020GL091709","DOI":"10.1029\/2020GL091709","article-title":"The TSIS-1 Hybrid Solar Reference Spectrum","volume":"48","author":"Coddington","year":"2021","journal-title":"Geophys. Res. Lett."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"359","DOI":"10.5194\/amt-11-359-2018","article-title":"Calibration of the DSCOVR EPIC visible and NIR channels using MODIS Terra and Aqua data and EPIC lunar observations","volume":"11","author":"Geogdzhayev","year":"2018","journal-title":"Atmos. Meas. Tech."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2019","DOI":"10.5194\/amt-12-2019-2019","article-title":"Cloud products from the Earth Polychromatic Imaging Camera (EPIC) observations: Algorithm description and initial evaluation","volume":"12","author":"Yang","year":"2019","journal-title":"Atmos. Meas. Tech."},{"key":"ref_36","unstructured":"GMAO (2021, May 10). MERRA-2 instM_3d_asm_Np: 3d, Monthly Mean, Instantaneous, Pressure-Level, Assimilation, Assimilated Meteorological Fields, Version 5.12.4, Global Modeling and Assimilation Office, Goddard Space Flight Center Distributed Active Archive Center (GSFC DAAC), 2015, Available online: https:\/\/disc.gsfc.nasa.gov\/datasets\/M2IMNPASM_5.12.4\/summary."},{"key":"ref_37","unstructured":"GMAO (2021, May 10). MERRA-2 tavg1_2d_rad_Nx: 2d, Hourly, Time-Averaged, Single Level, Assimilation, Radiation Diagnostics, Version 5.12.4, Global Modeling and Assimilation Office, Goddard Space Flight Center Distributed Active Archive Center (GSFC DAAC), 2015, Available online: https:\/\/disc.gsfc.nasa.gov\/datasets\/M2T1NXRAD_5.12.4\/summary."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2156","DOI":"10.1029\/2007JD009561","article-title":"Validation of the community radiative transfer model (CRTM) by using CloudSat Data","volume":"113","author":"Chen","year":"2008","journal-title":"J. Geophys. Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"2717","DOI":"10.5194\/gmd-11-2717-2018","article-title":"An update on the RTTOV fast radiative transfer model (currently at version 12)","volume":"11","author":"Saunders","year":"2018","journal-title":"Geosci. Model Dev."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1587","DOI":"10.1175\/1520-0442(1993)006<1587:TSCOLS>2.0.CO;2","article-title":"The Seasonal Cycle of Low Stratiform Clouds","volume":"6","author":"Klein","year":"1993","journal-title":"J. Clim."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2373","DOI":"10.1175\/MWR-D-11-00121.1","article-title":"Stratocumulus clouds","volume":"140","author":"Wood","year":"2012","journal-title":"Mon. Wea. Rev."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1949","DOI":"10.1175\/1520-0493(1994)122<1949:TSPCZA>2.0.CO;2","article-title":"The South Pacific Convergence Zone (SPCZ): A Review","volume":"122","author":"Vincent","year":"1994","journal-title":"Mon. Weather Rev."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1444","DOI":"10.1126\/science.1155121","article-title":"Forests and Climate Change: Forcings, Feedbacks, and the Climate Benefits of Forests","volume":"320","author":"Bonan","year":"2008","journal-title":"Science"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"e2019JD031488","DOI":"10.1029\/2019JD031488","article-title":"Daytime Variability of Cloud Fraction from DSCOVR\/EPIC Observations","volume":"125","author":"Marshak","year":"2020","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"e2020GL089221","DOI":"10.1029\/2020GL089221","article-title":"Subdiurnal to Interannual Frequency Analysis of Observed and Modeled Reflected Shortwave Radiation from Earth","volume":"48","author":"Feldman","year":"2021","journal-title":"Geophys. Res. Lett."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1114","DOI":"10.1175\/1520-0442(1997)010<1114:TROCDV>2.0.CO;2","article-title":"The Role of Cloud Diurnal Variations in the Time-Mean Energy Budget","volume":"10","author":"Bergman","year":"1997","journal-title":"J. Clim."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"2123","DOI":"10.1007\/s00382-015-2693-z","article-title":"Evaluation and intercomparison of clouds, precipitation, and radiation budgets in recent reanalyses using satellite-surface observations","volume":"46","author":"Dolinar","year":"2015","journal-title":"Clim. Dyn."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"319","DOI":"10.2151\/jmsj1965.70.1B_319","article-title":"Seasonal Heating of the Tibetan Plateau and Its Effects on the Evolution of the Asian Summer Monsoon","volume":"70","author":"Yanai","year":"1992","journal-title":"J. Meteorol. Soc. Jpn."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1007\/s00376-001-0007-3","article-title":"Interannual variability of atmospheric heat source\/sink over the Qinghai-Xizang (Tibetan) Plateau and its relation to circulation","volume":"18","author":"Zhao","year":"2001","journal-title":"Adv. Atmos. Sci."},{"key":"ref_50","first-page":"D05102","article-title":"Evaluation of multireanalysis products with in situ observations over the Tibetan Plateau","volume":"117","author":"Wang","year":"2012","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"3494","DOI":"10.1038\/s41598-020-60460-1","article-title":"Evaluation of Reanalysis Surface Incident Solar Radiation Data in China","volume":"10","author":"Zhang","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"e2019GL085782","DOI":"10.1029\/2019GL085782","article-title":"Causes of Higher Climate Sensitivity in CMIP6 Models","volume":"47","author":"Zelinka","year":"2020","journal-title":"Geophys. Res. Lett."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/22\/4595\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:30:41Z","timestamp":1760167841000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/22\/4595"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,15]]},"references-count":52,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["rs13224595"],"URL":"https:\/\/doi.org\/10.3390\/rs13224595","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2021,11,15]]}}}